CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Allowance for trade and other receivables	$ 368	$ 392
Common Stock [Member]
EQUITY
Common Stock, par value (in dollars per share)	$ 0.01
Common Stock, shares issued (in shares)	3,999
Common Stock, Shares Authorized (in shares)	6,000
Class B Stock [Member]
EQUITY
Common Stock, par value (in dollars per share)	$ 0.01
Common Stock, shares issued (in shares)	71
Common Stock, Shares Authorized (in shares)	530